Site Transition Scenarios

Each site and each ISP requires different steps during the transition
phase. This section provides some examples of site transition scenarios.

The first step to transition a site to IPv6 is to upgrade the name services
to support IPv6 addresses. For DNS, upgrade to a DNS server that supports
the new AAAA (quad-A), such
as BIND 4.9.4 and later. Two new NIS maps and a new NIS+ table have been introduced
for storing IPv6 addresses. The new NIS maps and NIS+ table can be created
and administered on any Solaris system. See IPv6 Extensions to Solaris Name Services
for details on the new databases.

After the name service is able to distribute IPv6 addresses,
you can start transitioning hosts. You can transition hosts in the following
ways:

Upgrade one host at a time. Use IPv4–compatible addresses
and automatic tunneling. No routers need to be upgraded. Use this method for
initial experimental transition. This method offers only
a subset of the IPv6 benefits. This method does not offer stateless address
autoconfiguration or IP multicast. You can use this scenario to verify that
applications work over IPv6. This scenario also verifies that the application
can use IPv6 IP-layer security.

Upgrade one subnet at a time. Use configured tunnels between
the routers. In this scenario, at least one router per subnet is upgraded
to dual. The dual routers in the site are tied together by using configured
tunnels. Then hosts on those subnets can use all the IPv6 features. As more
routers become upgraded in this incremental scheme, you can remove the configured
tunnels.

Upgrade all the routers to dual before any host is upgraded.
Though this method appears orderly, the method does not provide any IPv6 benefits
until all the routers have been upgraded. This scenario constrains the incremental
deployment approach.